/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Selections/QuadGridPatch.h
Compute the opening angle between the two quads in Column0 and Column1 of the given Row. This is based on the face normals of the two triangles connected to the edge between Column0 and Column1, so any non-planarity of the quads is ignored.
unsigned opening angle in degrees in range [0,180], where 0 means quads are parallel
double GetQuadOpeningAngleDeg ( const [FDynamicMesh3](API\Runtime\GeometryCore\DynamicMesh\FDynamicMesh3) & Mesh, int32 Column0, int32 Column1, int32 Row ) const